The Invention relates to 3-D imaging techniques.
The present invention provides a system for displaying moving images pseudostereoscopically. Such a system comprises a single source of sequential image information, e.g. on cinema film, videotape, digital video disk, computer memory, or the like. The image information is generally in the form of a series of image frames adapted to be displayed sequentially over a period of time. In accordance with the present invention, the image information does not contain stereoscopic information captured at the origin. That is, it does not contain images captured simultaneously from two vantage points nor does it contain any other source from which stereoscopic information may conventionally be derived.
In the system of the present invention, there are employed any of a variety of means for sequentially displaying a first series of image frames to one of the two eyes of an observer, and a second series of image frames to the other eye. For example, the observer (sometimes alternatively referred to as the xe2x80x9cviewerxe2x80x9d) may be provided with a headset having a pair of LCD displays, one in front of each eye; or two projectors may project differently colored or differently polarized light onto a theatre screen, and each observer would wear glasses having differently colored or differently polarized elements for the two eyes. Further examples and alternatives of such means are provided hereinbelow.
Just as in conventional stereoscopic display, at any particular point in time, two image frames, A and B, are displayed simultaneously, one to each of the observer""s eyes. However, in accordance with the present invention, image frames A and B are both generated from the single source of sequential image information. At a particular point in time, image frame A is derived from some particular source frame of the series of image frames in the single source of sequential image information. Call this particular frame F1. At that same point in time, image frame B is derived from a different source frame (F2) that is part of the same series of image frames in the source of sequential image information. The source frame F2 is located in the source of sequential image information to be displayed a certain amount of time after source frame F1 when the sequential image information is conventionally display, as, for example, by a video playback. Call that amount of time T. T is selected such that a typical observer experiences the display as a scene having depth.
The present inventor has found that for viewing typical content via cinema or video systems, the optimal amount of time T is between about 0.0167 and about 0.033 seconds. For example and not by way of limitation, when the left eye of the observer is shown frame F1, the right eye is shown a different frame, F2, which is on the same cartridge of videotape but spaced apart by a distance that corresponds with a time difference of about 0.0245 or 0.025 seconds. It is preferred to use 0.025 seconds as the interval.
The term xe2x80x98framexe2x80x99 as used herein applies to each xe2x80x98field,xe2x80x99 as that term is used in connection with NTSC or other forms of interleaved or interlaced television signals.
Some of the embodiments use polarized light to control which eye sees which image. In the light path to each eye, when planar polarization is employed, the planes of polarization are mutually perpendicular, so as to be complimentary to each other so that each eye does not see the image intended for the other eye.
As detailed herein, two identical images projected onto a screen which are horizontally offset from one another and polarized perpendicular to each other will appear somewhat three-dimensional to a viewer wearing polarized glasses because the image will appear in a different plane from the screen.
The present invention provides a system for displaying moving images pseudostereoscopically, comprising; a single source of sequential image information, comprising a series of source image frames adapted to be displayed sequentially over a period of time and not containing stereoscopic information captured at the origin of said series of image frames, a first means, for sequentially displaying a first series of display image frames to one of the two eyes of an observer; and a second means, for sequentially displaying a second series of display image frames to the other of the two eyes of an observer; and means for generating from said single source of sequential image information for simultaneous sequential display, an image frame A of said first series of display image frames and an image frame B of said second series of display image frames, wherein said image frame A is derived from a frame F1 of said series of source image frames and said image frame B is derived from a frame F2 of said series of source image frames, wherein said frame F2 is positioned in said single source of sequential image information to be displayed after said frame F1 by an amount of time T, the amount of time T being selected such that a typical observer experiences the display as a scene having depth.
The amount of time T is between about 0.0167 and about 0.033 seconds. The time T is preferably about 0.025 seconds.
The system preferably includes a screen on which the images are projected or otherwise displayed, the screen being at a distance D from an observer, wherein the image that is perceived by an observer upon binocular fusion of image frame A and image frame B when their content is identical appears to be at a distance from the observer that is different from said distance D.
In one embodiment, image frame A and image frame B are placed so that they appear to be in front of the screen. Alternatively, image frame A and image frame B are placed so that they appear to be behind the screen.
Landmark light is at least one of the following: a spotlight; a source of uniform illumination; a source of a pattern of illumination. Alternately, it is an illuminated frame placed near the display means.
It is preferable that said first means and said second means comprise means for providing first and second displays of image frames that are polarized complimentary to each other; and wherein said means for providing landmark light comprises a projector providing a non-polarized image derived from one of said source image frames.
Even without the landmark light, said first means and said second means preferably comprise means for providing first and second displays of image frames that are polarized complimentary to each other.
In another embodiment, there is means for detecting an object in successive source image frames; means E for detecting a change in a property of said object in successive source image frames; means for adjusting the display of image frame A and image frame B responsive to the output of said means E.
The methods and procedures of performing the present invention are also claimed by the inventor. The inventor regards as his invention, a method for pseudostereoscopically displaying moving images from a single source of sequential image information comprising the steps of: (a) providing a series of source image frames adapted to be displayed sequentially over a period of time and not containing stereoscopic information captured at the origin of said series of image frames; (b) sequentially displaying a first series of display image frames to one of the two eyes of an observer; (c) sequentially displaying a second series of display image frames to the other of the two eyes of an observer; and (d) generating from said series of source information frames for simultaneous sequential display an image frame A of said first series of display image frames and an image frame B of said second series of display image frames, wherein said image frame A is derived from a frame F1 of said series of source image frames and said image frame B is derived from a frame F2 of said series of source image frames, wherein said frame F2 is positioned in said single source of sequential image information to be displayed after said frame F1 by an amount of time T, the amount of time T being selected such that a typical observer experiences the display as a scene having depth.
In a further embodiment, the process continues with the additional steps of, (f) continually detecting an object in successive source image frames; (g) continually detecting a change in a property of said object in successive source image frames; and (h) continually adjusting the display of image frame A and image frame B responsive to the detected change in said property of said object.
In a first aspect of the aforementioned further embodiment, the property detected is vertical position that has changed between frame F1 and frame F2 and said adjustment is modifying said image frame B derived from F2 of said series of source image frames such that said change in vertical position of said object is eliminated.
In another aspect of the aforementioned further embodiment, said property is vertical position that has changed between frame F1 and frame F2 and said adjustment is modifying the value of time T to zero.
In another aspect of the aforementioned further embodiment, said property is horizontal position that has changed between frame F1 and frame F2 and said adjustment reversing polarity when the change in horizontal position would result in a typical observer experiencing the display as a scene having unrealistic depth.
Another way of looking at the present invention is as a three-dimensional viewing system capable of projecting a three-dimensional image onto a screen to be seen by an observer, comprising the steps of:storing at least one image in a buffer; displaying a buffer stored image on the screen at the same time the current frame is projected on the screen wherein two images are coded such that one image is directed to each eye of the observer, creating binocular fusion for the observer of all objects that have moved in time and space between the frames that are being simultaneously shown to the observer.
Yet another way of looking at an aspect of certain embodiments of the present invention is as a method of producing three-dimensional image information for subsequent viewing on a display in 3-D using software in a computer, wherein a user labels selected elements within a frame of image elements; wherein said software tracks selected image elements from frame to frame of image information; and produces a duplicate image of each labeled image item spaced at a distance from the original image item determined by the depth in three dimensions at which the selected image item is to appear after binocular fusion of the two images; wherein the said user can instruct said computer to change the depth at which an image item appears; wherein the software will alter the distance between the original image item and its duplicate so that, by binocular fusion, the viewer will see the image item changing depth as desired; wherein said image and its duplicate image are shown to the viewer such that the image is directed to one eye and the duplicate image is directed to the other eye, producing binocular fusion.